Field of the Invention
This document relates to a touch screen panel with a bent non-display region and a display device comprising the same.
Discussion of the Related Art
User interfaces (UI) enable humans (users) to interact with various types of electrical and electronic devices and easily control them as they want. Typical examples of the user interfaces include keypads, keyboards, mice, on-screen displays (OSD), and remote controllers with an infrared communication capability or radio frequency (RF) communication capability. The user interface technology is continuously developing to improve user sensation and ease of operation. Recently, user interfaces have been evolving into touch UI, voice recognition UI, 3D UI, etc.
The touch UI has been indispensably used in portable information appliances, and moreover it has been extensively applied in almost all types of home appliances. A capacitive touch sensing system can be used in a variety of applications, with its touch screen panel structure that offers higher durability and optical clarity than a traditional resistive touch sensing system and is capable of multi-touch detection and hover detection.
Hereinafter, a touch screen panel and an organic light-emitting diode display comprising the same will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view schematically illustrating a touch screen panel according to the related art. FIG. 2 is a view taken along line I-I′ of FIG. 1, which is a cross-sectional view schematically illustrating an organic light-emitting diode display comprising a touch screen panel according to the related art.
Referring to FIG. 1, a touch screen panel TSP comprises an electrode portion AA, a routing wiring portion NA, a pad portion PA, and a driving portion.
The electrode portion AA (or display region) comprises a plurality of touch sensors formed on a base film BF. The routing wiring portion NA (or non-display region) is located on the outside of the electrode portion AA. The routing wiring portion NA comprises a plurality of routing wires respectively connected to the touch sensors in the electrode portion AA. The pad portion PA is placed on one side of the base film BF. The pad portion PA comprises a plurality of pads respectively and electrically connected to the plurality of touch sensors through the plurality of routing wires. The driving portion comprises a touch integrated circuit and a flexible film LF. The touch integrated circuit sends and receives a touch signal for activating the touch sensors in synchronization with a control signal from a main board. To this end, one end of the flexible film LF is electrically connected to the pad portion PA of the base film BF, and the other end is electrically connected to the main board.
Referring further to FIG. 2, the organic light-emitting diode display according to the related art comprises a touch screen panel TSP and a display panel DP. The display comprises a display region AA where an image is implemented and a non-display region NA located on the outside of the display region AA.
The display panel DP comprises a thin-film transistor array TFA that has one or more thin-film transistors placed on a substrate SUB and organic light-emitting diodes electrically connected to the thin-film transistors. An organic light-emitting diode comprises an anode electrically connected to a thin-film transistor, a cathode placed opposite the anode, and an organic emissive layer interposed between the anode and cathode.
The touch screen panel TSP is placed on the display panel DP. The touch screen panel TSP comprises a first electrode Tx and second electrode Rx intersecting each other, with the base film BF between them. The first electrode Tx and the second electrode Rx are insulated from each other by the base film BF. Touch pads are placed on one end of the base film BF. The touch pads are connected to the first electrode Tx and second electrode Rx via routing wires. The touch pads are electrically connected to the driving portion.
The touch screen panel TSP and the display panel DP may be bonded together by an adhesive layer PSA interposed between them. A polarizing film POL is placed on the display region AA of the touch screen panel TSP.
Recently, an effort to reduce the bezel area BZ is under way to achieve a narrow bezel. But, it is necessary to make enough space for the pad portion PA and the driving portion, as well as the display region AA for implementing an input image, on a display device with a touch screen panel TSP. This space corresponds to the bezel area BZ, thus posing limitations when it comes to reducing the bezel area BZ when process margin, etc. is taken into account.
For example, the pad portion PA comprises a plurality of touch pads. To prevent damage to the polarizing film POL which may occur in a thermal compression process for bonding the touch pads and the flexible film LF, a preset process margin A is required between the touch pads and the polarizing film POL. The touch pads should be of sufficient width and length, in order to provide enough space B1 to avoid poor contact with terminals provided on the flexible film LF, taking into account alignment and process deviations from the terminals. Moreover, it is necessary to put a preset cutting margin B2 with respect to the edge of the base film BF in a blanking (or compressing) process for forming the touch pads. In addition, the flexible film LF connected to the touch pads is bent and placed around the edge of the base film BF, so there should be some space C between the edge of the base film BF and the flexible film LF.
As such, the organic light-emitting diode display comprising the touch screen panel TSP according to the related art has limitations in reducing the bezel area BZ without any structural changes since the above-described components have their own process margin in the non-display region NA.